The present invention relates to a lighting system such as a headlamp or a fog lamp which illuminates the forward part of a vehicle such as a car, and more particularly to a vehicle light apparatus which has the function of controlling a change in a lighting direction or a lighting area of a lamp light in response to a running situation and can properly carry out lighting in order to realize the safe running of the vehicle.
In order to enhance the running safety of a car, it is necessary to illuminate the running direction of a vehicle. A lamp for illuminating the forward part of a car such as a conventional headlamp or fog lamp of the car is constituted to illuminate the straight running direction of the car. In the case in which the car changes a course direction on an intersection road (a T-shaped road, a crossroad and so forth) or a curved road (an S-shaped road, a U-shaped road and so forth), therefore, the forward part of a course to be changed cannot be illuminated previously and a forward confirmation is carried out insufficiently so that there is a problem in respect of safe running. For such a problem, there has been proposed a lighting system in which a lighting range, that is, a lighting direction or a lighting area of a lamp is changed according to the steering operation of a car. For example, a lighting optical axis to be the lighting direction of a lamp for illuminating the forward part of a car can be changed transversely or a lighting area to be a range in which the lamp can carry out lighting can be changed, and furthermore, a steering angle (a steering angle of a steering wheel) which is closely related to the running direction of the car can be detected by a steering sensor for detecting the rotating angle of a steering wheel, for example, and the lighting direction of the lamp can be turned in the running direction of the car based on the detection output of the steering sensor or the lighting area can be enlarged in the running direction. Thus, the running direction of the car on an intersection road or a curved road can be illuminated previously, which is effective for safe running.
However, the conventional lighting system serves to control the lighting range according to a steering angle. For this reason, it is hard to carry out a proper lighting control to cope with various running situations of a car in some cases. For example, in the case in which running is carried out on a curved road having a small radius of curvature, it is desirable that a driver should confirm the situation of a curved road in a running destination earlier than the execution of a steering operation. In the conventional lighting system in which the lighting range depends on the steering angle, however, it is hard to enlarge the lighting range in a greater angular direction than an angle corresponding to the steering angle and the situation of the curved road of the running destination cannot be confirmed sufficiently in some cases. Therefore, there has been proposed a lighting system for earlier carrying out an illumination in a running direction when a steering operation is performed in the case in which a car runs on a curved road or an intersection road, which is effective for solving the problems. If the running direction is uniformly illuminated earlier in the lighting system of this type, the illumination in a straight running direction of a vehicle is reduced so that a safety confirmation in a straight running direction becomes insufficient. Also in the case in which the steering operation is carried out at the time of the start of the vehicle, moreover, an illumination in the directly forward direction of the vehicle is apt to be insufficient according to a steering angle or when the illumination is executed earlier. Also in the case in which the steering operation is executed, accordingly, it is preferable that an illumination should be performed in the straight running direction of a self-vehicle in such a manner that a safety confirmation can be carried out.
Moreover, the lighting system of this type is constituted to predict the running direction of a vehicle, thereby controlling a lighting range. In the case in which an error is made in the prediction of the running direction, particularly, the case in which the vehicle is predicted to be turned irrespective of straight running, the safety confirmation in the straight running direction is carried out insufficiently. In the case in which the vehicle is predicted to run straight when it is to be turned, it is hard to obtain an advantage that the earlier illumination in the running direction to be the benefit of the lighting system of this type is carried out and the lighting system of this type can function as a lighting system for an ordinary vehicle comprising no lighting system. Also in the former case, therefore, it is preferable that the safe confirmation should be maintained.
It is an object of the invention to provide a vehicle light apparatus which can automatically carry out a proper control of a lighting range in response to the steering operation of the vehicle and can reliably execute a safety confirmation in the straight running direction of the vehicle, there by performing a preferable illumination for the safe running of the vehicle.
The invention provides a vehicle light apparatus comprising a plurality of lighting means each of which illuminates forward a vehicle, lighting direction control means which changes a lighting range of said lighting means in response to a steering angle of the vehicle, and controls lighting directions of the lighting means independently or integrally in response to a running condition. More specifically, the lighting direction control means changes the lighting direction of a part of the lighting means and changes the lighting direction of the other part of the lighting means later than the part of the lighting means. For example, the lighting direction control means carries out a control such that the other part of the lighting means performs an illumination earlier in a straight running direction than the part of the lighting means when a steering angle is changed from a steering direction into the straight running direction. Alternatively, the lighting direction control means carries out a control such that the other part of the lighting means performs an illumination later in a steering direction than the part of the lighting means when a steering angle is changed from a straight running direction to the steering direction.
In the invention, moreover, the lighting direction control means includes running road predicting means for predicting a running direction of the vehicle and serves to control a change in each of the lighting directions when a running direction of the vehicle is guessed to be greatly changed by the running road predicting means.
According to the invention, when the vehicle changes the running direction by steering, the direction of the optical axis of one of the lighting means is deflected earlier and the direction of the optical axis of the other lighting means is maintained in the straight running direction in a running condition in which other cars or obstacles might be present in the straight running direction of the vehicle, and the direction of the optical axis of the other lighting means is deflected with a delay upon receipt of further steering. Consequently, it is possible to carry out an illumination in the running direction and the straight running direction of the vehicle respectively, which is preferable for maintaining safety running.